(1). Field of Invention
This invention relates to a pen; and more particularly relates to a pen with a retractable pen-cartridge (a retractable pen) that can elongate the length of its pen-body and project out the refill out of the pen point when the pressing part is pressed and provide sufficient length for holding the pen while writing, and shorten the length of the pen when the pressing part is pressed again to restore the refill in the pen point.
(2). Description of Related Art
Conventional retractable pens use either pushing or rotation for retracting/protruding its pen-cartridge and these retractable pens are normally designed to be long enough for easy writing. Their pen-body's length will provide difficulties to carry inside a small space (such as a packet, a wallet, or a purse). It is desirable to provide a retractable pen that has length adjustable capability—not only long enough for suitable handling the writing, but also short enough for easy carry.
Various devices have been disclosed to achieve this desirability. Among them, U.S. Pat. No. 6,832,868 (Dec. 21, 2004) to Hertwig and Nestlen describes a retractable pen whose triggering-device actuates the protrusion of its pen-cartridge, and, at the meantime, the same device actuates the lengthening its length; and vice versa by the same device after second another actuating step. However, the structure of the pen is complicate, and that of the triggering-device is mechanistically fragile. Accordingly, it is not only difficult to assemble/disassemble but also hard to perform routine maintenance by end users. It should thereby be appreciated to provide an improved triggering device for overcoming the above-mentioned shortcomings.